Cushioning assembly unit for back rests



Dec. 25, 1951 FREEMAN 2,579,918

CUSHIONING ASSEMBLY UNIT FOR BACK RESTS Filed Jan. 25, 1947 2 SHEETS-SHEET 1 INVENTOR. Pa an 0 d /7 M,4/v

Dec. 25, 195] R FREEMAN 2,579,918

cusmowmc ASSEMBLY UNIT FOR BACK RESTS 7 Filed Jan. 25, 1947 2 Sl-IEETS-SHEET 2 W 5; *3; 6% 4 Q. M

139% /25 Lek/A5 fqrrop/vzy scription.

Patented Dec. 25. 195i UNITED STATES PATENT OFFICE ousHIoNmG AssEMsLxuNIrFoR BACK RESTS 3 Roland J. :Freeman,:Ba-ldwin, N. .Y; Application January 25, 19417, Serial'No..724,e123

17 Claims. 1

This invention-relates to improvements in posture chairs, and more particularly toajback-rest cushioning mechanism therefor.

Posture chairs are ordinarily so constructed that the back-rest is either rigidly secured to the back post, oris hinged thereto in suchra way that :the movement of theback-rest can not be satisactori1y controlled. -In some casesa spring mechanism has been employed to return the backrest into approximate alignment with what may be described as theplane' of normalposture said spring mechanismmerving to return. said backrest \when released to the said plane.

l One-object of; this invention isza. posture .ehair which can be quickly andvsimply adjusted to the correct position ,of normal posture forany @user.

Another object-is a posture chair which cushiionshany movement of the back-rest out of the plane 1 of normalposture and back again.

Another object isa posture chair which can be manufactured at low costwithoutany sacrifice in strength or durability.

Another object is. a posture .chair of. relatively few and simple parts.

Another object is aposture chair which is.-

simple in construction and operation, inexpensive to. manufacture, light in weight, compact, easy to dismantle and pack for, shipment to unpackand reassemble, to'manipulate, and. which is very eificient and. durable in use.

Anotherobject is a. cushioning assembly unit for resilientlydemountably mounting a backrest ,uponthe back post .of ;a';post-ure chair.

detailed de- .Other objects :will appear from the .Inthe accompanying drawings consisting of {tWO sheets of four figures, numbered Figs. .1 to 4 @inclusive, one convenient. form of the-invention has. been illustrated.

Fig. -1 is a perspective view of a back-rest cushioning mechanism;

Fig; 2 is'a'hor-izontal cross-sectional view taken along the line 2-2 of Fig. 1, looking in the direction of the arrows;

' Fig.3 is anendVlewof the bracket-assembly looking-from'the left of Fig. 2, withcertain of the parts omitted; and

Fig. 4' is aside viewof a'posture chair and its undercarriage,- with the base or pedestal omitted.

Like reference characters designate corre sponding parts throughout the several fi'guresof the drawings.

' Referring -to Figs; 1to4, theposturechair 30 includes-a back rest 3i, shaped to conform-, generally to-thesmall of'the 'ba'ckandto furnish 1 ative to the chairbase-or pedestal.

support therefor. The back-resttl is mounted upon a backwpost 43 (Fig. 4') by means of the cushioning assembly unit "3 3. The backpost' 43--is substantially'L-shaped, and is bent to conform generally tothe contour of the body whenseated. The back post may be made of any preferred material such as bar steel which renders-the back post inherently resilienti The-seat 32 is supported upon a spider assembly unit H15 which includes a standard H5 (Fig.4), supported in a chair base or pedestal (not-shown) of -any conventional type. The standard 5* is male threaded to efiectheight adjustment rel- "The back post-'43 is preferably-mounted in a "back "post holder H1 which is pivoted at 125-425 to the U shaped frame 1 flit-of the spider assembly I05. The back post dil -normally assumes the plane of correct posture under the influence of 20 the holder -t|1-whi6h is actuated by the spring "132; The back-rest 3| "is adjustably supported upon the back post 43, and-is normally retained in theplaneof correct posture for any person of normal physique by the cushioning assembly unit33:

ln general, to adjust the back-resti3l (Fig. 4) to thetcorrectipostural position for a particular individual, two adjustments are desirable. namely the iateral distance between the seat- 32 and the I back post 43-preferably should be adjustable {for -girth,-and,the height'of the backrest' 31 above thelevelofthe seat32 preferably should. be adjustable along back -post 43 for body or trunk length.

Thelateral adjustment of the seat 32 maybe elteeted-by making the seat 32 slidable in and out upon the spider assembly H15; while the height adjustment of the back-rest 3! maybe effected byforming a vertically'elongated slot 44 (Fig. ll in the back post 43 to allow verticalslid- $.44 formed in'the .back post 43. 'lihestud .31 terminates in a threaded shank 40 adapted to receive cup and said cover.

of normal posture.

hand wheel 45 is drawn up, the bushing 38 is 1 compressed between the face of the bracket 34 and the face of the washer 39. When the hand wheel 45 is screwed tight upon the threaded shank 40, the cushioning unit 33 is clamped to the back post 43 between the washer 42 and the annular shoulder of the stud 31, the squared shank 4| is seated in the slot 44 to prevent any rotation of the cushioning assembly unit 33, and any swinging movement of the back-rest about the pintle 36 will be cushioned by the compression of the elastic bushing 38.

The hand wheel 45may consist of a threaded nut 43 seated in a metal cup 41 and anchored therein by crimping the peripheral marginal edge ofthe cover 46 over the peripheral marginal edge of the cup 41 to clamp the nut 48 between said The cup 41 and cover 46 are provided with centrally disposed openings which register with the threaded opening in the nut 43.

By this arrangement the back-rest 3| is rockably supported upon the pintle 36, so that whenever the back-rest 3| is rocked responsive to body pressure the angular position of the bracket 34 changes relative to the pintle 36, thus varying the pressure applied to the elastic bushing 38 by the bracket 34, to cushion the movement of the back-rest 3| and of the body upon the back post 43. When body pressure is removed from the back-rest 3|, the elastic bushing 38 resumes its normal shape and restores said back-rest to the plane of normal posture.

The bushing I3I spaces the holder III away from the bracket III), the separation between the fixed bracket H and the pivoted holder II'I effected by the bushing I3I being such, that when the spring I32 is tensioned sufiiciently to retain the holder II! and the bushing |3I against the bracket III), the back post 43 which is mounted in the holderlII will be positioned in the plane Thus, with the bushing |3I in place and the spring I32 under suflicient tension to force holder II'I upwards against bushing I3 I, the back post 43 will always be positioned in the correct plane for a person of normal posture, and this adjustment, once effected, is a fixed setting. This fixed setting may be changed by substituting a thicker or thinner bushing |3I between the bracket I I0 and the holder Ill. The

' tension appliedtothe spring I32 by the hand wheel I33 determines the body pressure required -to move the holder III away from the bushing I3| to move the back post 43 off normal.

To dismantle the back post 43, the hand whe I33 is released, the spring I32, bushing |3I and bolt I are removed, and a machine screw (not shown) which passesthrough the holder I I1 into the back post 43 is removed. The back post 43,

cushioning assembly unit 33, and the back-rest 3|, may now be detached from the posture chair 30 as a single unit, or the assembly unit 33 may also be detached from the back post 43 by un- By this arrangement, the posture chair 30 can be quickly dismantled to facilitate compact shipment without affecting the spider assembly unit I05, and can be reassembled just as quickly at the delivery point.

While the cushioning assembly unit has been illustrated in combination with one preferred form of posture chair, it may if desired be mounted upon the back post of any other conventional form of posture chair.

The back post is biased by the spring I30 against the bushing I3I to normally retain the back post and therefore the back-rest in the plane of normal posture. The back post only moves out of the plane of normal posture responsive to body pressure and then only against increased tension of the coiled spring, I30, whose tension may be regulated manually by 'the hand wheel I33. Body pressure tends to tilt the backrest upon the back post, but the elastic bushing tends to resist and to cushion this rocking movev Operation The threaded standard H5 is mounted in the pedestal or chair base (not shown) to regulate the height of the seat above the floor level. The lower end of the back post is inserted in the back post holder I I! with the bolt hole in the back post in registry with the correspondingly disposed hole in the holder I IT. The carriage bolt I33, bushing |3|, spring I32, and hand wheel I33 are assembled as shown in Fig. 4, with the carriage bolt I30 (Fig. 4) seated in the bracket III). Hand wheel I33 is manipulated to tension the spring I32 and rock the back post holder In about its pivots I25-|25 until the post holder is biased against bushing I3I. The squared shank 4| of the stud 31 of the cushioning assembly unit to which the back-rest 3| is attached, is inserted through the elongated slot 44 in the upper end of the back post and the hand wheel 45 is left loose until the lateral adjustment of the seat 32 relative to the back-rest, and the vertical adjustment of the back-rest along the back post relative to the posture chair 30 to the position of correct posture (normal postural position) of said occupant by two adjustments, namely: (a) the in and out adjustment of the seat upon the frame I I16 of the undercarriage, and (b) the up and down adjustment of the back-rest upon the back post. When these two settings have been properly made, the surface of the back-rest provides support for the back of an occupant of normal posture without conscious physical effort on such occupants part, and regardless of said occupants physical proportions. j r j When the occupant moves from the position of correct posture, the body pressure applied to the back-rest changes the angular position of the back post against the increased tension of the coiled spring I30, and the elastic bushing 38 now functions to cushion the back-rest to the occupants back. The elastic bushing, in producing a the cushioning action, functions in efiect as a shock absorber. 'When the occupant resumes the position of correct posture the backfpost returns to the plane of normal posture-andthe backrest returns to the position of normal posture thereby fremorving pressure ;:from, the occupants hack. 1

:Thusawhen the posture chairhas been once adjusted to an occupants normal postural ,requirements, .tsaidi occupant, may enjoy normal postural; support without conscious forit or inconvenience.

physical ef- Whatisclaimedis: ..1.,;A, cushioning assembly .unit comprising a bracket adaptedfor attachment. to the back-rest of-a posture chair; castud, oneiend of said stud beingaadapted to be detachably inserted inthe Jslottedrback post 'ofta: posture chair. for vertical :sliding movement in said slot, said bracket being ,rrockably mounted .upon the, opposite end of said stud, .anelastic c bushing. mounted between said a stud Ends'andsaid bracket in rocking being .opeerabl'eiin conjunction with said back-post to compress said bushing to, cushion. movement of a backerestwhen attached thereto.

, 2. A cushioning assembly unit comprising a bra'cketya stud arpintle fastened to one end of said stud and journalled in said bracket, the opposite end of said stud being reduced to form a shoulder asquared shank and a screw-threaded shank, saidthreaded shank being adapted, to be inserted through an elongated slot in a support ..with said squaredrshank-slidably engaging the side walls oisaid slot, a hand wheel screw-coupled torsaidthreadedshank to clamp said support bet'weensaid hand wheeland said shoulder, and an elastic bushing mounted concentric with said stud, saidbracket being rockable on said pintle to compress said bushing against said support to cushion the movement of said bracket. p. 3. A cushioning assembly unit comprising a bracket, a stud, a pintle fastened to one end of said stud and journalled in said bracket, the 0p posite endof said stud being reduced to forma shoulder a squared shank'and a screw-threaded shank, said threaded shank being adapted to be inserted throughua slotted support with said squaredeshank slidably engaging the side walls oisaidslot, a hand wheel screw-coupled to said threaded shank to clamp 'said support between :said handwheel and saidrshoulder, an elastic bushingmounted concentric'i-with said stud, said bracket being rockable on'said pintle to compress s'aid bushing and cushion the movement of said bracket, and meanscontrolled by said hand wheel and associated with said stud for regulating the V elasticity ofsaid bushing.

f "bracket, and a washer mounted on said stud and abutting said support and said bushing, said bracket being' rockable on said pintle to compress. said bushing against said washer thereby cushioning the movement of said bracket.

5. A cushioning assembly unit for a chair back-rest comprising a bracket, a stud, one end of said stud being pivotally supported upon said bracket, the opposite end of said stud being reduced and partially threaded to form a shoulder a squared shank and a male-threaded end, an

3 whereon threaded end, and means co-operating with the elastic bushingireely l slidablygmounted on; said stud, said squared shank being ,mountable i n ;;a

, support to. retain said. bushing upon said stud, .and abandwheel-screwecoupled to the :malethreaded end of, said shank to clamp said support betweensaid hand wheel and said shoulder to locksaid squared shank, in said support, and

of :said stud, the opposite end of said studbeing free, an, elastic bushing, a washer, saidbushing and said washer being slidably mounted onsaid stud to compress said bushing between said bracket and said washer to oppose and cushion pivotal movement of said bracket relative; to said stud, means whereon said stud is supportable from, its free end, andineans operable to clamp thefree end of said stud to said supporting means and to reduce the spacing between the washer and the bracket to compress the :bushing.

7. In a posture chair and, in combination, a stud, a bracket pivotally mounted upon one end of said stud, the opposite endof said stud-being free, a rubber bushing, a washer, said bushing and said washer being slidably mounted on-said stud to compress said bushing between said bracket and; said washer to oppose and; cushion pivotal movement of said bracket relative to said stud, means whereonsaid stud is supportable from its-free end, and means operable to clamp the free end of said stud to said supporting means and to reduce the spacing between the washer and the'bracket to compress thebushing.

8. In a posture chair and in combinations stud, abracket pivotally mounted upon one end of said stud, the opposite end of said stud being screw-threaded, an elastic bushing, a washer, said bushing and said washer being slidably mounted on said stud, said washer thus being operable to compress said bushing againstsaid bracket to oppose and cushion pivotal movement of said bracket relative to said stud, means said stud is supportable near its screw-threaded end of said stud to clamp-said stud to said supporting'means and to draw said washer against said supporting means and said bracket towards said washer to compress the bushing.

9. In a posture chair andfiin "combination, a stud, a bracket 'pivotally mounted upon one end of said stud, the opposite end of said stud being male-threaded, a rubber bushing, a washer, said bushing and said washer being slidably mounted on said stud, said washer being operable to compress said bushing against said bracket to Onpose and cushion pivotal movement of said bracketrelative to said stud, means for supportmg said stud adjacent its male-threaded end,

and means co operatingwith said male-thread to clamp said'stud against said supporting means and to compress said bushing between said 7 washer and said bracket.

post of a posture chair for vertical sliding movement'in said slot, means for clamping said stud to the back post, said bracket being rockably mounted upon the opposite end of said stud, and an elastic bushing mounted on said stud and 75 compressed by the bracket against the back post to oppose and cushion the rocking movement of said bracket upon said stud.

11. A cushioning assembly unit for a posture chair having a back-post-supported back-rest comprising a bracket adapted for attachment to the back-rest, a stud, one end of said stud being adapted to be inserted in the slotted back-post for vertical sliding movement in said slot, means for clamping said stud to the back-post, said bracket being rockably mounted upon the opposite end of said stud, and a rubber bushing mounted on said stud and compressed by said bracketlagainst the back-post under control of said clamping means to oppose and cushion rocking movement of said bracket upon said stud.

12. A' cushioning assembly unit comprising a bracket, a stud, a pintle fastened to one end of said stud and journalled in said bracket, an elastic bushing concentrically mounted upon said stud in -abutment with said bracket, the opposite end of said stud being reduced to form a shoulder a squared shank and a screw-threaded shank, said threaded shank being adapted to be inserted through an elongated slot in a support with said squared shank slidably engaging the side walls of said slot and said bushing abutting said support,'and a hand wheel screw-coupled to said threaded shank to clamp said support between said hand wheel and said shoulder and to draw said bracket towards said support to compress said elastic bushing for opposing and cushioning turning movement of said bracket upon said pintle.

13. A cushioning assembly unit for a posture chair having a back-post-supported back-rest comprising a bracket, a stud, a pintle fastened to one end of said stud and journalled in said bracket, a rubber bushing concentrically mounted upon said stud and abutting said bracket, the opposite end of said stud being reduced to form a shoulder a squared-shank and a screw-threaded shank, said back-post having an elongated slot formed therein, said squaredshan'k being slidably adjustable in said elongated slot, and a hand wheel screw-coupled to said threaded shank and co-acting therewith to draw said bracket towards said back-post to tighten said squared-shank in said slot and to compress said bushing, and said compressed bushing opposing and cushioning turning movement of said bracket upon said pintle.

14. A cushioning assembly unit for a posture chair having a back-post-supported back-rest comprising a stud, a bracket pivotally supported upon one end of said stud, an elastic bushing mounted upon said stud and compressible against said bracket to oppose and cushion pivotal movement of said bracket, the opposite end of said stud being reduced to form a shoulder and a squared shank and terminating in a malethread, said back-post having a slotted opening formed therein, said squared shank being mountable in said slotted opening to retain said bushing upon said stud, and a hand wheel screwcoupled to the male-thread of said stud and 8 upon one end of said stud, arubber bushing mounted upon said stud and compressible against said bracket to oppose and cushion pivotal movement of said bracket, the opposite end of said stud being reduced and partially threaded to form a shoulder and a squared shank terminating in a male-thread, said back-post having a slotted opening formed therein, said squared shank being mountable in said slotted opening to retain said bushing upon said stud, and a hand wheel screw-coupled to the malethread of said stud and when tightened co-opcrating therewith to lock said squared shank in when tightened locking said squared shank in said slotted opening and drawing said bracket towards said back-post to compress said bushing.

15. A cushioning assembly unit for a posture chair having a back-post-supported back-rest comprising a stud, a bracket pivotally supported said slotted opening andto draw said bracket towards said back-post to compress said bushing.

16. In a posture chair and in combination, a.

back-post, a slotted opening formed in said backpost, a stud, a bracket pivotally supported upon one end of said stud, an elastic bushing, a washer, said bushing and said washer being mounted upon said stud, said bracket and saidwasher being relatively movable to compress said bush ing and thus oppose and cushion movement of said bracket upon its pivotal support, .the. opposite end of said stud being reduced and partially threaded to form a shoulder a squared shank and a male-threaded end, said squared shank being mounted in said slotted opening to position said washer against said back-post, and a hand wheel screw-coupled to the malethreaded end of said stud and co-acting therewith to retain said squared shank in said slotted opening and to draw said bracket towards said washer to compress said bushing.

17. In a posture chair and in combination,v a support, a slotted opening formed in said support, a stud, a bracket pivotally supported upon one end of said stud, a rubber bushing, a washer, said bushing and said washer being 'mounted upon said stud, said bracket and said washer being relatively movable to compress said bushing and thus oppose and cushion movement of said bracket upon its pivotal support, the, opposite end of said stud being reduced and partially threaded to form a shoulder a squared shank and a male-threaded end, said squared shank being positioned in said slotted opening to fix said washer against said support, anda hand wheel screw-coupled to the male-threaded end of said stud and co-acting therewith to retain said squared shank in said slotted opening and to draw said bracket towards said fixed washer to compress said bushing.

ROLAND J. FREEMAN.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,775,433 Krabol Sept. 9, 1 930 1,929,201 Frohlich Oct. 3, 1933 2,056,965 Herold Oct. 13, 1936 2,208,561 Jungbauer July.23, 1940 2,430,709 Devorss Nov. 11, 1947 FOREIGN PATENTS Number Country Date 510,613 Germany Oct. 21, 1930 

